1. Field of the Invention:
The present invention relates to a timepiece having a calendar mechanism and, more particularly, to a timepiece having a small, thin calendar mechanism that prevents erroneous operation of a day indicator.
2. Description of the Prior Art:
Referring to FIG. 19 and FIG. 20, the conventional timepiece with calendar mechanism, e.g. a movement (mechanical body) 400 of an analog electronic timepiece, has a main plate 402 structuring a base plate of the movement 400. A dial 404 (shown by the virtual line in FIG. 20) is attached on the movement 400.
In the analog electronic timepiece, of the opposite sides of the main plate 402, the side the dial 404 exists is referred to as a xe2x80x9cback sidexe2x80x9d of the movement 400 and the side opposite to the side having the dial 404 is referred to as a xe2x80x9cfront sidexe2x80x9d of the movement 400. The train wheel assembled on the xe2x80x9cfront sidexe2x80x9d of the movement 400 is referred to as a xe2x80x9cfront train wheelxe2x80x9d and the train wheel assembled on the xe2x80x9cback sidexe2x80x9d of the movement 400 is referred to as a xe2x80x9cback train wheelxe2x80x9d.
On the xe2x80x9cfront sidexe2x80x9d of the movement 400 are arranged a battery, a circuit block, a step motor, a front train wheel, a switch device (all not shown). By the rotation of the step motor, the front train wheel is rotated.
A center pipe 402a is provided on the main plate 402. An hour wheel 410 is provided rotatable relative to the center pipe 402a, and rotates twice per day due to rotation of the front train wheel. A date indicator driving wheel 412 is provided to rotate once per day due to rotation of the hour wheel 410.
A date indicator 420 is provided rotatable relative to the main plate in order to indicate date. The date indicator 420 has a date-indicator teeth portion 422 having 31 teeth and a date plate 424 printed with characters to indicate date. A day indicator 430 is provided rotatable relative to the main plate to indicate day of the week. The day indicator 430 has a day star wheel 432 having 7 or 14 or 21 teeth and a day plate printed with characters to indicate day of the week.
The date indicator driving wheel 412 is provided with a date feed finger 414 capable of rotating the date indicator 420 by one day per day and a day feed finger 416 capable of rotating the day indicator 430 by one day per day.
The date feed finger 414 is structured integral with the date indicator driving wheel 412 through a date feed finger spring portion 414b. The day feed finger 416 is structured integral with the date indicator driving wheel 412 through a day feed finger spring portion 416b. 
The date feed finger 414 is structured to rotate not to enter a rotation path of the day star wheel 432.
However, in the conventional timepiece with calendar mechanism, unless the date feed finger is arranged not to enter a rotation path of the day star wheel, the date feed finger will mesh with the day star wheel resulting in a fear of erroneously operation of the day indicator.
Furthermore, in order to reduce the planar size of the timepiece with calendar mechanism while avoiding erroneous operation of the day indicator, there is a need to secure sufficiently great a gap in a thickness direction between the date feed finger and the day star wheel, which tends to increase the thickness of the timepiece.
Therefore, in order to solve the foregoing drawbacks in the conventional art, it is an object of the present invention to realize a small-and-thin type timepiece with a calendar mechanism that prevents erroneous operation of the day indicator.
Another object of the invention is to realize a timepiece with a calendar mechanism provided with such a date feed mechanism that the date feed finger can positively rotate the date indicator.
In order to solve the above problem, the present invention is, in a timepiece with calendar having a main plate structuring a base plate of a movement, a date indicator rotatably provided relative to the main plate to indicate date and having a date indicator teeth portion, a day indicator rotatably provided relative to the main plate to indicate day of the week and having a day star wheel, and a date indicator driving wheel rotating once per day to enable the date indicator to rotate by an amount of one day per day and the day indicator to rotate by an amount of one day per day, characterized in that: the date indicator driving wheel having a date feed finger capable of rotating the date indicator by an amount of one day per day and a day feed finger capable of rotating the day indicator by an amount of one day per day; the date feed finger being structured integral with the date indicator driving wheel through a date feed finger spring portion; the day feed finger being structured integral with the date indicator driving wheel through a day feed finger spring portion; the date feed finger being structured to rotate passing on main plate side of the day star wheel of the day indicator; wherein provided is a date feed finger guide portion to secure meshing in a thickness direction between the date feed finger and the date indicator teeth portion when the date feed finger meshes with the date indicator teeth portion.
Also, in the timepiece with calendar mechanism, the date feed finger guide portion is preferably provided on a back side of the main plate.
Also, in the timepiece with calendar mechanism, a slant surface is preferably provided in a portion that the date indicator driving wheel rotates and the date feed finger first contacts the date feed finger guide portion.
Also, in the timepiece with calendar mechanism, a semispherical convex portion is preferably provided in a portion that the date feed finger contacts the date feed finger guide portion.
Also, in the timepiece with calendar mechanism, the day feed finger is preferably structured to pass through on a dial side of the date indicator teeth portion, and the day feed finger being structured to rotate contacting the date feed finger guide portion in order to secure a gap in a thickness direction between the day feed finger and the date indicator teeth portion when the day feed finger rotates through the dial side of the date indicator teeth portion.
By the foregoing construction, in the timepiece with calendar mechanism, there is no fear of erroneous operation of the day indicator so that the date feed finger can positively rotate the date indicator. Further, by the foregoing construction it is possible to realize a small, thin timepiece with a calendar mechanism.
Also, in the timepiece with calendar mechanism, preferably provided in place of providing the date feed guide portion are a date feed finger guide groove portion to secure a mesh amount in a thickness direction between the date feed finger and a feed operating tooth portion when the date feed finger meshes with the feed operating tooth portion to be fed, an inner guide portion to prevent a decrease of the mesh amount between the date feed finger and the feed operating tooth portion and an outer guide portion to prevent an increase of the mesh amount between the date feed finger and the feed operating tooth portion.
By providing an inner guide portion, it is possible to effectively prevent a mesh amount between the date feed finger and the operating tooth portion from decreasing more than required. Also, by providing an outer guide portion, it is possible to effectively prevent a mesh amount between the date feed finger and the operating tooth portion from increasing more than required. Accordingly, by thus structuring, the date feed finger can positively rotate the date indicator.
Also, in the timepiece with calendar mechanism, preferably provided is a date feed forward gap secure portion to secure a gap in a planar direction between the date feed finger and a feed waiting tooth portion when the date feed finger rotates through a point near the feed waiting tooth portion to be next fed.
By the foregoing construction, it is possible to eliminate the fear that prior to date the date feed finger erroneously operates the date indicator.
Furthermore, in the timepiece with calendar mechanism, preferably provided is a date feed rear gap secure portion to secure a gap in a planar direction between the date feed finger and a feed end tooth portion when the date feed finger rotates through a point near the feed end tooth portion having been fed.
By the foregoing construction, it is possible to eliminate the fear that after date the date feed finger erroneously operates the date indicator.
Also, in the invention, preferably the timepiece with calendar mechanism is structured as an analog electronic timepiece, the timepiece with calendar mechanism having a quartz oscillator structuring source oscillation and a step motor to rotate the front train wheel, the step motor being structured to include a coil block, a stator and a rotor, and one part of the quartz oscillator and one part of the coil block being arranged to overlap with the date indicator.
By the foregoing construction, in the timepiece with calendar mechanism, because one part of the quartz oscillator, one part of the coil block and date indicator can be arranged compactly, a small, thin timepiece with a calendar mechanism can be realized.